1. Field of the Invention
The present invention relates to lubricating systems for conveying equipment, and more particularly to an automatic lubricator for a conveyor system that includes a conveyor chain and an associated conveyor chain track.
2. Description of the Related Art
Different types of automated conveying systems are known in the art. One type of known conveying system comprises a plurality of interconnected links which run along appropriate guides. U.S. Pat. Nos. 4,436,200 and 5,586,644 show examples of this type of conveying system.
In order for these types of conveying systems to run as smoothly as possible, the friction between the lower surfaces of the interconnected links and the guide surfaces must be minimized. Also, the friction between the lower surfaces of the interconnected links and the guide surfaces must be minimized in order to reduce wear in the links and the guide.
Various methods have been proposed for limiting the friction between the lower surfaces of the interconnected links and the guide. For instance, manual application of a lubricant to the guide surfaces and the links has always been a possible, though labor-intensive, option to minimize friction. As an alternative to manual lubrication, certain conveying systems have used links or guides made from special materials that have minimal surface roughness and are wear resistant. As another alternative to manual lubrication methods, many operators of conveyor systems have used various devices for automatically applying lubricating fluid to the links of a conveyor chain. For example, U.S. Pat. Nos. 3,785,456, 3,869,023, 4,085,821 and 4,368,803 disclose automatic devices for dispensing lubricating fluids to a conveyor system or a conveyor chain. A more recent solution to the problem of lubricating a conveyor chain and its associated guides can be found in U.S. Pat. No. 5,779,027, which discloses the use of lubrication inserts that form a lubricating film between the links of a conveyor chain and the surface of the guides that direct the conveyor chain.
Most known automatic conveyor lubricating systems, including many of the systems mentioned above, require the use of some type of detecting device that initiates a lubrication cycle when tripped by a portion of the conveyor chain. Often, an installer of this type of conveyor lubrication system must secure a detector or a mechanical trip to the conveyor chain, and also relocate electrical, hydraulic or pneumatic lines in order to supply a source of power to the lubricating system. Depending on the complexity of the lubricating system, the installation and maintenance costs of the lubricating system may actually exceed the cost of periodically manually lubricating the conveyor chain and conveyor chain guide. As a result, the users of conveying systems may not opt for automatic lubrication devices as the benefits of automatic lubrication are outweighed by installation and maintenance costs.
Therefore, in view of the cost and complexity of existing automatic conveyor chain lubricators, there is a continuing need for conveyor systems having alternative automatic lubricators for the conveyor chain and its associated conveyor chain track.
It is therefore an object of the present invention to provide a conveying system with an automatic conveyor chain and conveyor chain track lubricating system that provides an alternative to manual lubrication methods and to the use of conveyor chain links or guides made from special materials.
It is still another object of the present invention to provide conveying system with an automatic conveyor chain and conveyor chain track lubricating system that may be operated without attention and maintenance.
It is yet another object of the present invention to provide a conveying system having an automatic conveyor chain and conveyor chain track lubricating system that may be operated without the need for conveyor chain detecting devices that trigger a lubrication cycle.
It is still another object of the present invention to provide an automatic conveyor chain and conveyor chain track lubricating system that may be easily installed at virtually any location along the length of the conveyer chain guide track thereby providing maximum flexibility in the placement of the lubricating system.
It is a further object of the present invention to provide an automatic conveyor chain and conveyor chain track lubricating system that may be easily installed at virtually any location along the length of the conveyer chain guide track without the need to supply electrical, pneumatic or hydraulic lines to the lubricator.
The foregoing needs are satisfied and the foregoing objects achieved by a conveyor system that comprises an endless conveyor chain, a guide track, a lubricator, and a support frame. The guide track is carried by the support frame, and has a bottom wall and opposed sidewalls that extend upward from the bottom wall. The bottom wall of the guide track has a guide surface and an aperture. The conveyor chain is comprised of interconnecting links, and is supported by the guide track for movement within the guide track. Each of the interconnected links of the conveyor chain has a lower surface that may contact the guide surface of the guide track when the conveyor chain is moved by a drive motor and sprocket. The lubricator is mounted on the support frame, and includes a separator dividing the lubricator into a chamber for storing lubricant and a gas compartment. The separator is movably mounted in the lubricator spaced from and movable towards an outlet of the lubricant chamber. The lubricator includes an electrochemical cell in the gas compartment for generating gas when the cell is connected to a source of electric current such as a battery. The gas flows into the gas compartment and against the separator to move the separator against the lubricant in the chamber to force the lubricant out through the outlet. One type of lubricator having these features is shown in U.S. Pat. Nos. 4,023,648 and 4,671,386.
An adapter block and piping are typically used to place the outlet of the lubricator in fluid communication with the aperture in the bottom wall of the guide track. First, the adapter block is assembled to the bottom surface of the guide track. The adapter block has ports in fluid communication with an opening in a projection that extends outward from the adapter block. When the adapter block is assembled to the guide track, the projection fits into the aperture in the bottom wall of the guide track. After the adapter block is assembled to the guide track, a fluid path between the lubricator and a port of the adapter block is constructed by way of piping. As a result, a fluid path between the outlet of the lubricator and the aperture in the bottom wall of the guide track is established.
In operation of the conveyor system, the drive motor and sprocket pull the conveyor chain relative to the guide track such that the conveyor chain traverses the guide track. Movement of the conveyor chain in the guide track causes frictional forces between the guide surface of the guide track and the lower surface of each link that contacts the guide surface. In order to allow the conveyor chain to run smoothly in the guide track and also minimize wear of the lower surface of each link and the guide surface, the lubricator is activated to automatically supply lubricant to the guide track and links. Lubricant exits the lubricator, and travels through the adapter block and the opening in the projection of the adapter block. Lubricant moves through the aperture in the bottom wall of the guide track, and covers areas of the guide surface near the aperture. When the links pass over areas of the guide surface near the aperture, the lower surfaces of the links contact the lubricant and a lubricating film is formed between the guide surface of the guide track and the lower surface of each link that contacts the guide surface of the guide track.
The lubricating film minimizes frictional forces between the guide surface and the lower surface of each link and thereby allows the conveyor chain to run smoothly in the guide track and also minimizes wear of the lower surface of each link and the guide surface of the guide track. Because the lubricator operates continuously, the links and guide surface of the guide track are kept well lubricated without the need for maintenance personnel to lubricate the chain and guide track by hand. Also, there is no need for the relocation of pneumatic, hydraulic or electrical lines as the lubricator operates as self-contained unit within the conveyor system.